uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The role of aluminium additions in the oxidation and wear of a TaC:C low-friction coating
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
Show others and affiliations
(English)Manuscript (Other academic)
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:uu:diva-92117OAI: oai:DiVA.org:uu-92117DiVA: diva2:165081
Available from: 2004-09-10 Created: 2004-09-10 Last updated: 2016-04-22
In thesis
1. Synthesis and Evaluation of TaC:C Low-Friction Coatings
Open this publication in new window or tab >>Synthesis and Evaluation of TaC:C Low-Friction Coatings
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In the large family of carbon-based coatings there are members capable of providing a rare and very desirable combination of high wear resistance and low friction. The field of application for this kind of coatings is steadily increasing which, naturally, give raise to new questions and demands.

Coatings of this type can be produced in a number of different ways, but the parameter influencing their properties most is the chemical composition. To facilitate investigations of the compositional impact on the synthesis and properties of coatings, a way to alloy magnetron-sputtered thin films was developed in this thesis. It does not involve the use of reactive gases or additional material sources; instead metallic foils are attached onto the magnetron target surface and thus sputtered alongside the target material. This co-sputtering route was later used to synthesize carbon coatings alloyed with Ta, Zr, W and Al in various amounts and configurations.

It was shown that the co-sputtering method could be used to alloy coatings in a very simple and straightforward manner, with excellent possibilities of controlling the amount of alloying elements. The process temperature could be kept as low as 70 °C.

Carbon coatings alloyed with transition metals (MeC:C) displayed polycrystalline nanocomposite structures with 5 nm metal carbide crystallites in a matrix of near-amorphous carbon. Alloying with Ta resulted in a radical 80 % reduction in friction coefficient during dry sliding in air, from 0.22 for pure carbon to 0.04 for TaC:C. This was found to be due to facilitated graphitization and the formation of lubricating surface oxides. Al additions to TaC:C resulted in a transformation of the TaC phase to a metastable, previously unreported Ta1-χAlχC. The coefficient of friction remained unaltered, but the oxidation rate compared to TaC:C was significantly reduced due to the formation of AlTaO4 instead of Ta2O5.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2004. 49 p.
Series
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 1011
Keyword
Materials science, Materialvetenskap
National Category
Materials Engineering
Research subject
Materials Science
Identifiers
urn:nbn:se:uu:diva-4544 (URN)91-554-6034-8 (ISBN)
Public defence
2004-10-01, Siegbahnsalen, Ångströmlaboratoriet, Polacksbacken, Uppsala, 09:15
Opponent
Supervisors
Available from: 2004-09-10 Created: 2004-09-10Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Wiklund, Urban

Search in DiVA

By author/editor
Wiklund, Urban
By organisation
Applied Materials Sciences
Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 870 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf